A number of big names will be speaking at Search Engine Strategies, a Chicago conference focusing on search engine marketing, starting today.

The conference’s opening keynote address will be presented by Lawrence Lessig, professor of law at Stanford Law School where he teaches and writes about constitutional law, contracts and the law of cyberspace.

Lessig is the founder of the school’s Center for Internet and Society which is designed to help law students and the general public with educational resources regarding law, technology and public interest.

Also addressing the conference will be Josh James, CEO and co-founder of Omniture, an online business optimization company with over 4,700 customers across 75 countries. In the past few years, James has won a number of business awards including the 2006 Ernst & Young Entrepreneur of the Year Award and the 2007 American Business Award for Best Executive.

Bill Tancer, New York Times bestselling author and general manager of global research at Hitwise will also speak this week. Tancer pens a weekly online column for Time called The Science of Search and is regularly quoted in the press in such publications as USA Today and Business Week.

Search Engine Strategies, which runs through December 12, comprises more than 60 sessions covering beginner to advanced search marketing strategies.